Continuous tank furnace



Nov. 28, 1933. T. c, -McKlNLEY ET AL 1,937,390

CONTINUOUS TANK FURNACE l Filed Feb. 26, 1925 2 Sheets-Sheet l N0V- 28, 1933 T. c. MCKINLEY ET A1.

CONTINUOUS TANK FURNACE Filed Feb. 26, 1923 2 Sheets-Sheet 2 Patented Nov. .28, 1933 UNiTE-o sites CONTINUOUS TsNK FURN'ACE Thomas C. McKinley and Clarence A. Rhonelznus', Qharleston, Vv. Va., Vassignors,toLibbeyeOwens vFord Glass Company, '.lfolediigg tion of Ohio liio. a servirte" Applicstirebruaryzs', 1923"., serial No. -621,139

24 Claims.

llhis invention relates to improvementsin continuous tank furnaces, and more particularly 'to such a furnace designed to furnish molten glass simultaneously" to a plurality of sheet glass drawing machines.`

ln the process of drawing sheet glass, it has been customary to provide a separate glass melting unit for. each sheet drawing machine. This unit would consist of an elongated ,tank furnace,

ai comprising n1eltingrefining and cooling chambers. The glass producing materials are fed into the melting end of the furnace, where intense heat is applied and the materials fused into molten glass. This molten glass flows slowly through the refining and cooling chambers, wherein it settles and cools until it has acquired the proper hcmogeniety and plasticity to ,be drawn into sheet forni. Avery. careful and prolonged treatment of 'the molten glass is required to secure Jthe nearly perfect quality necessaryY for producing clear and uniform sheets ofv glass. A Very large quantity of glass must be maintained in molten condition in this tank, andthe cost of melting and subsequently heating `this glass is considerable.

It has .long been realized that it wouldioemore economical to supply two or more machines from a single furnace, since va-rf-:latiizely small increase in the sizeof the tank,`a1.1d the fuel consumption, would enlarge its capacity suficiently to supply the extrainachine. However, attempts to 4feed twov machines .from spaced points at thev end of the cooling or refining .cham` whereas the inner portion, that is the sidenearer the other machine, would be fed from ,the hotter,

more freely .flowing glass, at theycenterofthe tank. Also, Aseine.'portion of thiscentralrglass ilow is stopped or .retarded by the .division wall at the end of. the tank .between the two machines.

This-glass becornes V donnant .or stagnant,. and

deteriorates Ain quality, thus adversely affecting thesheetfwhen it 'finally 4is yraiifn 'thereinta For these, and" other reasons not'conipletelyinderstood, it 'was in'ipos's'ible'to obtain high'qualty sheets-of glass onthe machines bwhen'supplied from tllis'type of furnace. y Q'Ihe present invention overcomes the vdii'fcultie's vind ic' :atfed' above, and discloses a system whereby a'pluralityof machines r'nay be successfully fred from afsingle furnace unit. The inventionv comprises angesiri'the Q structure of fthe tank itself, whereby` practically the" entre 'coolingV and refining portions of the furnac' ear'e"sfplit up into a 'series' of separate channels, one; for Sach inachinejff'Each channel -isa prolongation of a portion ofthe c onrn'ion' Vrn'elting,tar'lk", but the channeli'sfquitejdis'tinctinitself frin'veach ofthe other channels, having its own' walls and cover arch. In this way the glass at both sides ofthe channel `will metwith the ysanietem'pe'ifaiue ,conditions and. mantel 'i'e'fsfdati and both sides of nie-sheet in 'the machine vente `fed .uniformly ,and equally. The entire' furnace 'wit .Combinesihe esninies 0f e srlelefnieltins tank,.'with'the :advantages 'of separate rening and coolinstanksfor each .mathle- The H101- ten glass frornthenieltin .chamber floyvsw'ithout `material interruptionmdirectly into the nindividual .channels It.. each chantal tfieslass flows. directly', and gevenyt, its. ,pertilllar "nechine,` practically fthe 'entire Vrefining and *cooling .process eine performed ndividuai1y-fo'each machine. "i i y .Advantage is Laken' @fills .ltlely Small widthsof the severalchannels, to make radical andadvantaesous adv', ses .in .the temperature commi Sistem. The @ver arohesoysr the. Ghan- .nelsl are',` droppedrnueh lowerthan the, coyer arch oyerthe ineltingftank. v,The division wall thus necessitated.adjacent the'n entrance of the channels act'sto restrict the flow of heated gases from theinelting chamber into uthe severalsreining chair-bers. orphelines'. ,This wallmay be @steeded down ,nle'air'lyg to y the glass level, ariggserves" not only to confine the heated gases to the ,melting chamber, but v also ,reflectsy Yand radiatesthe heat `.diretecl.t,heresains@ backihtolhemellig @hmger.r Sincefthislwalldoes not extend down into the fio-.ving ses ities .1.1.0 impeleg effecten ,this

flow. There is nothing to stop the free and uninterrupted flow of the glass from the melting point until reaches the machines, except the division wall between each pair of channels. This retarding effect, being conned to the melting chamber where the heat is intense, is not serious, as any stagnant or dormant glass will be melted out before it flows into the channels.

Gther objects and advantages of this invention will become apparent from the following detailed description of one approved embodiment thereof. '1n the accompanying drawings:

Fig. 1 is a plan view of the lower glass-holding portion of the furnace unit, the upper side walls and cover arches being removed.

Fig. 2 is a vertical longitudinal section through the tanks, taken substantially on the lineV 2-2 of Fig. l.

Fig. 3 is a transverse verticall section on an enlarged scale taken substantially on the line 3 3 of Fig. 2.

The melting tank is shown at 1, the two refining tanks or channels at 2, and the cooling chambers at 3. As here illustrated, the furnace is feeding molten glass to two sheetglass drawing machines of the well-known Colburn type, as disclosed in the patent to Colburn, 1,248,809, granted Dec. fl, 1917. The glass flows out from the cooling chamber into a shallow open draw-pottkfrom which the glass sheet 5 is drawn upwardly and bent into the horizontal plane over a bending member 6. Obviously, this is merely illustrative of one use of this furnace, which might also furnish molten glass for other types of sheet-drawing machines, or even for machines producing other forms of glass articles. The furnace is particularly designed however for use with sheet-glass drawing machines, whereit essential that a uniform, evenly-tensioned now of homogeneous glass of high quality be delivered tothe machine, in order to produce the best quality of sheet glass.

That portion 1 of the furnace between the front Ywall 7 and the int rmediate wall 8 is referred to as the melting tank, and is constructed much the same as previous tanks of this type for supplying a single machineQeXcept that it is of somewhat greater dimensions. The glass producing materials, known as batch or cullet, are fed into the tank through the extension or dog-house 9, and these materials are melted by the heated gases furnished by the regenerators 10. Five pairs of these regenerators are indicated in the drawings but this number is merely illustrative, and sometimes fire is not maintained in all of the regenerators with which the furnace is provided. Sufficient heat is furnished to melt the materials, (which melting process takes place mostly in the forward portion 11 of tank 1), and to maintain the melted pool of glass in the tank at the desired temperature.

The molten glass flows slowly from the tank 1, lthrough the rear portion of the furnace where the reningand cooling ofthe glass takes place. This rear portion of the furnace, is divided into duplicate or twin tanks by the spaced vertical walls l2,- with intervening open space 13. These walls 12 extend from the rear ends 14.- of therening tanks or channels to points beneath the intermediate wall 8, where they are joined by vertical wall 15. It will be noted from Fig. 2 that the bottoms of tanks 1 land 2 are continuous prolongations of oneanother so that the molten glass has an unbroken .flowfrom the melting tank to and through the renning tanks. The cooling chambers 3, as in former practice, are of considerably found that the tanks operate very enciently wii f.-

nel is set out somewhat beyond the line less. depth than the melting and refining chambers, so that only the refined surface strata of the glass now on through the cooling chambers to the draw-pots 4.

The cover arches 16 for the channels 2 are dropped considerably lower than the cover arch 1'! of the melting tank, the intermediate wall 8 closing the space therebetween down to the tank wall Preferably, this wall 8 will be eX- tended down to jack-arches 18 closely above the surface of the molten glass.- In this way, the heating chamber above the molten glass in the melting tank is practically cut off from the channels A2, and the heating gases will be largely conned to the melting chamber where a much higher temperature is desired. Furthermore, the inner face 19 of the wall S will reflect and radiate heat back onto the glass in the melting chamber 1, thus increasing themelting efficiency of this tank.

If preferred, lioaters 29, (indicated in dotted lines in Figure l) may be positioned in the melting chamber 1 adjacent the entrance of the cha nels 2, to skim ori any scum or unmelted mate-` rials on the surface glass. However, it has been out these floaters, and as the presence of .foreign bodies in the molten glass always tends to injure the glass, it is questionable whether the benefits derived fror. skimming the glass are not more than offset by the lines and blemisies iinparted by the iioaters themselves. The of su i oaters is optional.

After the molten glass has passed into the the draw-pot much the same as in the s portions of a single unit installation. The in side walls 12 will offer snbstant lly the saine irictional resistance to rlowimT glass the outer walls 21.

, The radiation between the closely adjac walls l2, will maintain t? ese inner walls and molten glass adjacent thereto at a somewhat higher temperature than the o'iter walls 2l the glass 2.2 at the outer sides ofthe s earns. lt will be noted that the outer wall 21 of each chanthe wall of melting tank l, thus slightly extending the outer portion 22 of the stream of glass moving toward the cooling chamber. Thus the outer side of the stream iiowing into the coo chamber will draw from a line which is so: what removed from the outer wall 21, and temperature substantially the same as that at inner side of the stream adjacent inner wall Thus the molten glass will be to the two sides of the source of sheet 5, at uniform ratesl and at uniform temperatures, and the 5 will pull smoothly and evenly, as if it were fed from the central flow of a single tank.

From the above, it will be seen that the rear portion of this furnace unit functions much the same and has all of the advantages of a pair of separate independent tanks, one for each machine. The refining and cooling process is practically individual to each machine. However, *be expensive melting process is carried t in J- 7 tile vmately to the glass level.

1,937,390 f ly the cost of two single furnace units,`and obviously the concentration and` elimination of par-ts A will greatly decrease the factory overhead and -labor costs.

While an installation .has been described, by way of example, designed for two machines, by obvious changes it could be adapted for three or more machines. i

'Applicants are aware that single furnace units; have already been designed and used for supplying a plurality of glass-gathering holes for handplants for blowing glass-cylinders, also for supplying a plurality of mechanical glassblowing machines. The use of a single glass supply channel from which a series of sheet-glass drawing machines, are fed,lthe glass being reheated betweenk each pair of machines has also been proposed. r None of these prior devices, however either disclose or suggest `the construction or method of flowing glass, presented in this, application, and the several advantages of this invention as. described above were neither contemplated nor obtained in any of these old furnaces.

We claim: l. The. method of providing molten glass for a plurality of sheet glass drawing machines, consisting in melting the glass-formingmaterials in a single pool, owing the molten glass therefrom in separate streams, one to each machine, maintaining a melting heat above the pool but shielding the streams from thisy heat, and separately refining and cooling the glass in each stream to therproper working condition.

2. A tank furnace for supplying molten glass y to sheet-glass drawing machines, comprising a continuous elongated tank consisting of melting, refining and cooling chambers, the molten glass flowing freely from the melting chamber to and through the refining and cooling chambers to the machine, the cover arch for the refining chamber being much lower than the cover arch for the melting chamber,V and a division wall between the melting and refining chambers4 extending from the cover arches approximately down to the glass level.

3. A continuous tank furnace for supplyingV molten glass to a plurality of sheet-glass drawing machines, the tank l'comprising a melting end and a refining and cooling end from Vwhich the machines are supplied, substantially the entire refining and cooling portions being divided into a series of separate channels, one for each machine,

each channel having individual walls and cover` machines are supplied, substantially the entire refining and cooling portions being divided into a series of separate channels, onefor each machine, each channel having individual walls and cover arches, the cover arches Vfor the channels being considerably lower than the` cover arch for the melting chamber, andan intermediate division wall between the mel-ting'and refining chambers extending from the cover arches approxi- 5. A continuous tank furnace for supplying molten glass to a plurality ofsheet-glass drawing machines, the tank comprising a melting end and arefining andcooling endfromwhich the machines are suppliedsubstantially the entire refining and cooling por-tions being `divided into a series of separate channels, one for each machine, each channel having individual walls and cover` arches,` vand intermediate `means between the melting kand refining chambers to restrict the flow of heated gases tothe refining chamber without impeding the flow of the molten glass.

6. A continuous tank furnace for supplying molten glass to av pair of sheet glass drawing machines, the furnace comprising a melting tank, a pair ofA separate parallel refining tanksV through which the molten glass flows from the melting tank, and a pair `of cooling chambers through Ywhich the glass flows from the refining tanks, the

entrances to the cooling chambers being 'closer to the adjacent inner side walls of the refining tanks than to the outer side walls thereof.

7. A continuous tankV furnace for supplying molten glass toa plurality of sheet glass drawing machines, the tank comprising a melting end and a .refining and coolingV end from which the machines are supplied, substantially the entire relining and cooling portions being divided into a series of separate channels, one for each .machine, each channel having individual walls and cover-arches, said refining channels being offset along their outer. edges in and for the manner specified.

`8. A tank furnace for supplying molten glass lto sheet glass drawing machines, comprising a continuous elongated tank, consisting of a melting chamber, rening chambers and cooling chambers, the molten glass lfiowing freely from the melting chamber to and through the refining and cooling chambers to the-machine, the coverarch for the refining chamber being much lowerv than the cover-archfor the melting chamber, and a division wall between the melting and refining chambers extendingvfrom the cover-arches ap- 9;,A continuous'tank furnace for `supplying "I molten glass to a plurality of sheet glass drawing machines, the tank comprising a melting end and a refining and cooling end from which the machinesare supplied, substantially the entire relining and cooling portions. being divided into i two separate cooling chambers, one `for each machine, said cooling chambers being in offset relation with respect tothe refining chambers toward the center of the melting tank thereof.

10. In a furnace construction, a single elongated melting `tank in which the molten glass is produced, a pair of spaced substantially parallel refining tanks connected to one end of the melting'tank and extending forwardly therefrom in the samev general direction, said refining tanks `thereof-and extending in the same general direction therefrom, said refining tanks being independent and in spaced parallel relation with respectto one another, a cooling chamber connected to the forward end of each refining tank,`

and a working receptacle connected to the forward end of eachvcooling chamber,V said rening tanks, cooling chambers and working receptacles being in. substantialalignment with one another and with said melting tank to constitute substantial continuations of the latter so that the glass is caused to fiow in separate substantially straight unbroken paths from the melting tank through said rening tanks and cooling chambers into said working receptacles, each working receptacle receiving glass from its respective refining tank and cooling chamber only.

v12. In sheet glass apparatus, a single melting tank in which molten glass is produced, a plurality of refining tanks connected to one end thereof and extending in the saine general direction therefrom, said refining tanks being in dependent and in spaced parallel relation with respect to one another, a cooling chamber connected to the forward end of each renning tank, a working receptacle connected to theiforward end of each cooling chamber, said refining tanks, cooling chambers and working receptacles being in substantial alignment with one another and with said meltingtank to constitute substantial continuations of the latter so that the glass is caused to flow in separate substantially straight unbroken paths from the melting tank through. refiningtanks and cooling chambers into said working receptacles, each working receptacle receiving glass from its respective refining tank and cooling chamber only, and means associated with each working receptacle for form'- ing a sheet of glass therefrom, said sheet extending transve 1sely of said receptacle and also transversely of the flow of glass thereinto.

13, In a furnace constructiona single melting tank in which molten glass is produced, a plurality of refining tanks connected to one end thereof land extending forwardly therefrom Vin substantial alignment therewith, a cooling charnber connected to the forward end.- of Yeach refining tank, and a working receptacle'connected to the forward end of each cooling chamber, each working receptacle receiving glass from its respective refining and cooling chamber only,

refining tanks, cooling chambers andworkingv receptacles being in substantial alignment with onel another so that the glass is caused to iiow therethrough in separate substantially straight unbroken paths.

le. ln sheet glass apparatus, a single melting which molten glass is produced, a plurality of refining tanks connected to onewen'd thereof and extendingV forwardly therefrom in substantial alignment therewith', a cooling charnber connected to the forwa d end of each refining tank, a working receptacle connected to the forward end of each cooling chamber, each workreceptacie receiving glass from its respective refining and cooling chamber only, said refining tanks. cooling chambers and working receptacles being in substantial alignment with one another so that the glass is caused to flow therethrough in separate substantially straight unbroken paths, and means associated with each working receptacle for forming a sheet of glass therefrom, said sheet extending transversely of said receptacle and also transversely of the line of now of glass thereinto.

15, A continuous tank furnace for supplying molten glass to a pair of sheet glass forming machines, comprising a melting tank, a pair of parallel refining tanks, passages connecting the ischarge end of the melting tank with the re-4 ceiving ends of the refining tanks, and coolingl chambers connected to said refining tanks, the center lines of the passages 'being closer together than the center lines of the refining tanks and the center lines of the cooling chambers being further apart than the center lines of saidpassagesbut closer together than the center lines of said refining tanks..

16. In a furnace construction, a single melting tank in which molten glass is produced, a plurality of refining tanks connected to one end thereof and extending in the same general direction therefrom, said refining tanks being independent and in spaced parallel relation with respect to one another, a relatively shallower and narrower cooling chamber connected to the forward end of each refining tank, and a relatively shallower working receptacle connected to and in communication with the forward end of each cooling chamber, said refining tanks, cooling chambers working receptacles being in substantial alignment with one another and with said melting tank to constitute substantial continua'tions of the latter so that the glass is caused to flow in separate substantially straight unbroken paths from the inciting tank through said refining tanks and cooling chambers into said working receptacles, each working receptacle recei g glass from its respective refining tank and cooling chamber only.

17. In a furnace construction, a single melting 'tank in which molten glass is produced, a pair of spaced substantially parallel refining tanks connected to one end of the melting tank and extending forwardly therefrom in the same general direction, a relatively shallower cooling chamber connected to the forward end'of each refining tank, and a 'working receptacle connected to the forward end of each cooling chamber, each working receptacle receiving glass from its respective refining tank andcooling chamber only, said refining tanks, cooling chambers, and working receptacles being in substantial alignment with one another so that the glass is caused to fiow therethrough in separate substantially straight unbroken paths.

18. In a furnace construction, a single melting tank in which molten glass is produced, a

pair of spaced substantially parallel refining tanks connected to one end of the melting tank and extending forwardly therefrom in the same general direction, a cooling chamber connected to the forward end of each refining tank, and a workin receptacle connected to the forward end of each cooling chamber, said receptacle being relatively shallower than the rening tank, each working receptacle receiving glass from its respective rening tank and cooling chamber only, said refining tanks, cooling chambers and working receptacles being in substantial alignment with one'another so that the glass is caused to flow therethrough in separate substantially straight unbroken paths.

19. In a furnace construction, a single melting tank in which molten glass is produced, a

1roV

receiving glass from its respective refining tank and cooling chamber only, said refining tanks, cooling chambers and working receptaclesrbeing in substantial alignment with one another so that the glass is caused to iiow therethrough in separate substantially straight unbroken paths.

20. In a furnace construction, a single melting tank in which molten glass is produced, a

pair of spaced substantially parallel refining tanks connected to one end of the melting tank and extending forwardly therefrom in the same general direction, a relatively narrower cooling chamber connected to the forwarden'd of each refining tank, and a Working receptacle connected to the forward end of each cooling chamber, each working receptacle receiving glass from its respective rening tank and cooling chamber only, said refining tanks, cooling chambers, and Working receptacles being in substantial alignment with one another so that the glass is caused to flow therethrough in separate substantially straight unbrokeny paths.

2l. In a furnace construction, a single melt ing tank in which molten glass is produced, a pair of spaced substantially parallel refining tanks connected to one end of the melting tank and extending forwardly therefrom in the same general direction, a cooling chamber connected to the forward end of each refining tank, and a working receptacle connected to the forward end of each cooling chamber, said receptacle being relatively narrower than said refining tank, each working receptacle receiving glass from its respective refining tank and cooling chamber only, said refining tanks, cooling chambers and working receptacles being in substantial alignment with one another so that the glass is caused to flow therethrough in separate substantially straight unbroken paths.

22. In a furnace construction, a single melting tank in which molten glass is produced, a pair of spaced substantially parallel refining tanks connected to one end of the melting tank and Yextending forwardly therefrom in the same gredients in a single pool, flowing the molten glass from said pool in a plurality of separate streams through individual refining zones, in independently refining the glass in each stream, in then reducing the Width and depth of each stream and fiowing the same through a cooling zone into a Working zone, and in causing saidA separate streams of glass to fiow through the rening and cooling zones and into said workwhich consists in melting the glass batch inA ing zones through substantially straight unbroken parallel paths. v

24. The process of producing molten glass which consists in melting the glass batchl ingredients in a single pool or substantial depth, flowing the molten glass from said pool in a plurality ofV separate streams through individual refining zones, in independently rening the glass in each stream whiie maintaining the depth of said stream substantially equal to that of said single pool, in then reducing the Width and depth of each stream and flowing the same through a cooling zone, in further reducing the depth of each stream and flowing the samefrom said cooling Zone into a Working zone, and in causing said separate streams of glass to flow through the rening and cooling zones and into substantially 

